The circulating blood cells are formed from the totipotent hematopoietic stem cell (HSC) present in the bone marrow. Recently methods have been established to isolate a fairly pure population of HSCs from both human and mouse bone marrow. The specific aim of this project is to develop a minimal deviation totipotent human hematopoietic stem cell line. These cell lines will be developed by transfecting HSC population, isolated from human cord blood, with a combination of oncogenes using a very high efficiency gene transfer method developed at Clonexpress. These cell lines would be extremely useful to understand the development of the hematolymphoid system, and in the discovery of new cytokines. The stem cells would help in the development of new strategies for gene and cell replacement therapy.